松辽盆地长岭断陷龙凤山次凹下白垩统营城组物源与沉积相研究

发布时间：2018-01-07 06:38

  本文关键词：松辽盆地长岭断陷龙凤山次凹下白垩统营城组物源与沉积相研究　出处：《天然气地球科学》2017年01期 　论文类型：期刊论文

  更多相关文章： 物源 重力流 沉积相 营城组 龙凤山次凹

【摘要】：根据岩心、测井、地震、录井和薄片等资料,明确龙凤山次凹营城组的物源方向和沉积相类型,结合古地貌格局、同沉积断裂活动和古气候特征,对研究区沉积相时空演化进行了研究。研究结果表明,龙凤山次凹营城组沉积时期发育3个物源区,分别为西南部的变质岩物源区、南部的中基性岩浆岩物源区和东南部的岩浆岩物源区。研究区营城组沉积相类型以扇三角洲相和近岸水下扇相为主。扇三角洲相发育于湖盆洪水面和风暴浪基面之间的滨浅湖环境中,沿扇体展布方向从碎屑流、浊流沉积转化为牵引流沉积;近岸水下扇相发育于风暴浪基面之下的半深湖—深湖环境中,沿扇体展布方向从滑动滑塌逐渐转变为碎屑流和浊流沉积。研究区古地貌南高北低,坡度自西向东逐渐变陡,来自东南物源区的碎屑物质沿陡坡滑动滑塌快速入湖,形成近岸水下扇相;受同沉积断裂活动的影响,断裂两盘高差增大,在古地貌上形成向湖盆深处延伸的断槽,来自西南和南部物源区的碎屑物质受洪水搬运并沿断槽深凹处堆积,形成扇三角洲相;受古气候逐渐温热潮湿的影响,季节性洪水频发,导致研究区西南断槽带和南部断槽带发育进积为主的扇三角洲相砂砾岩体,东南陡坡带营Ⅴ砂组沉积时期开始发育进积为主的近岸水下扇相砂砾岩体,不同沉积相类型的砂砾岩体连片分布,紧邻东北洼陷带的半深湖—深湖相泥岩,形成研究区良好的源储对接关系。
[Abstract]:According to the core, logging, seismic, logging and thin slice data, the source direction and sedimentary facies types of the Longfeng Mountain Suwa Yingcheng formation are determined, and the sedimentary fault activity and paleoclimate characteristics are combined with the paleogeomorphic pattern. The spatiotemporal evolution of sedimentary facies in the study area has been studied. The results show that three provenances of metamorphic rocks originated from the southwestern metamorphic rocks were developed in the Sedimentary period of the Subsaw Yingcheng formation in Longfeng Mountain. The sedimentary facies of Yingcheng formation are mainly fan delta facies and nearshore underwater fan facies. Fan delta facies are developed on the flood surface of lake basin and storm wave base. Between the shallow lake environment. Along the distribution direction of fan body from clastic flow to turbidite deposition into traction flow deposition; The near-shore underwater fan facies developed in the semi-deep lacustry-deep lacustrine environment below the storm wave surface, and gradually changed from sliding collapse to clastic flow and turbidite deposition along the spreading direction of the fan body. The paleogeomorphology in the study area is high and low in the north and south. The slope gradually steeped from west to east, and the debris from the southeastern provenance slid into the lake along the steep slope, forming the near-shore underwater fan facies. Influenced by the synsedimentary fault activity, the height difference between the two plates of the fault increases, forming a fault trough extending to the deep part of the lake basin on the paleogeomorphology, and the debris material from the source area of the southwest and the south is transported by the flood and accumulates along the deep concave of the fault trough. Forming fan delta facies; Due to the influence of paleoclimate, seasonal floods occur frequently, which leads to the development of alluvial fan delta sandstones in the southwestern and southern fault troughs of the study area. During the depositional period of Ying鈪，

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